Buffer device with energy discharge means

ABSTRACT

A buffer device for automatic guns resiliently stops a reciprocating bolt in the recoil position, returns a sufficient portion of the stored energy back to the bolt for return thereof to battery position at a velocity that effects a desired rate of fire, and then discharges the remaining stored energy by mechanical means.

U United States Patent l 13,568,565

[72] Inventor Henry P. Swieskowski [56] References Cited Manda, UNITED STATES PATENTS [2]] Appl. No. 778,490 I [22] Filed Nov 25 1968 2,590,897 4/1952 Simpson 89/198X 4s 1 Patented Mar. 9,1971 FOREIGN PATENTS [73] Assignee I The QuitedStatesofAnrer-iea, as G, l 13,53X 2/1955 Germany V 198 represented? the Secretary Army Primary Examiner-Benjamin A. Borchelt Assistant Examiner-Stephen C. Bentley Attorneys-Harry M. Saragovitz, Edward J. Kelly, Herbert Berl and Albert E. Arnold, Jr.

[54] DEVICE WITH ENERGY DISCHARGE ABSTRACT: A buffer device for automatic guns resiliently stops a reciprocating bolt in the recoil position, returns a suffi- 8 Chums 5 Drawing Figs cient portion of the stored energy back to the bolt for return [52] US. Cl 89/198 thereof to battery position at a velocit that effects a desired Y [51] Int. Cl F4ld 11/12 rate of fire, and then discharges the remaining stored energy [50] Field ofsearch ..89/ 130, 198 by mechanical means.

2.6 28 29 22 72 7O 54 56 l i l I @UWlElR DEVllCE Wl'flii ENERGY DISCHARGE MEANS The invention described herein may be manufactured, used, and licensed by or for the Government for governmental purposes without the payment to me of any royalty thereon.

With most automatic guns, especially those which fire high velocity cartridges that create considerable recoil reaction, buffer devices are utilized to stop a reciprocating member energized by cartridge discharge forces at the end of its recoil stroke and then return a portion of the energy back to the member so that it can complete its operating cycle, thereby reducing the adverse effects of the high recoil force when the member impacts with another in its counterrecoil travel. V

The present forms of these buffer devices reduce the energy in the reciprocating member by converting the excessive energy therein to heat through frictional and/or viscous resistant forces, which is destructive and therefore is less than perfect for use in weapons where positive and trouble-free operation is mandatory. Moreover, in these buffer devices expensive and precision fabricated components are required to produce the proper resistant force whether the devices be based on mechanical or hydraulic principles.

it is therefore a principal object of this invention to provide for automatic guns a buffer device which stops a recoiling member by absorbing the energy therein and then returns to the member only sufficient energy for it to complete its operating cycle at a predetermined velocity with remaining energy transferred to the buffer being discharged, still in its mechanical form, free of the member.

It is a further object of this invention to provide a buffer device which duplicates the action of friction-type buffers but without converting any of the energy to heat and which can be fabricated at a fraction of their cost.

Further objects and advantages of the invention will be apparent from the following specification and the accompanying drawings which are for the purpose of illustration only and in which:

FIG. 1 is a schematic view of a machine gun which includes the buffer device of this invention and shows the gun ready to be fired;

F IG. 2 is a fragmentary, schematic view of the buffer device showing the relationship of the component members thereof just before contact by recoiling bolt;

FIG. 3 is a view similar to FIG. 2 but shows the relationship of the members when the bolt is stopped in its recoil position by transfer of the energy therein to the buffer spring;

FlG. 4 is a view similar to FIG. 2 but shows the members when the spring is partially recovered and a sufficient amount of the stored energy therein is transferred back to the bolt for return to its battery position and the spring is seared to prevent further recovery and release of the energy therein; and

FlG. 5 is a view similar to FIG. 2 view but shows the spring released to discharge the remaining energy stored therein free of the counterrecoil traveling bolt.

Shown schematically in the drawings is an automatic gun 12 of blowback type comprising a receiver 14, a barrel 16 for chambering for discharge a cartridge 18 having a case 29 which is set back in the barrel by discharge forces, and a bolt 22 arranged to be energized by setback of the case for reciprocal travel between a forward battery and a rearward recoil position. A restraining device 24 releasably retains bolt 22 in battery position and buffer device 26 resiliently stops the bolt in recoil position and energizes it for return travel to battery position.

Buffer device 26 is preferably assembled as a unit for easy assembly to and disassembly for gun l2 and includes a cylindrical housing 26 with interrupted threads 29 provided thereon for releasable attachment to receiver l4. Slidingly mounted in housing 28 for displacement along the extended axis of movement of bolt 22 is a plunger 36 having a cylindrical body portion 32 and a stem 34 of smaller diameter which extends coaxially forward therefrom and which forms an annular shoulder 36 at the front end of the body portion. A mating bore 38 through the front end 40' of housing 28 receives stem 34 and forward displacement of plunger 30 in the homiing is limited by contact of shoulder 36 with the front end. A compression spring 42 is mounted in housing 28 in coaxial alignment with plunger 30 so as to act thereon through a plate 44 secured to the front end of the spring. Plate 44 includes a cylindrical portion which is inserted within the coils of spring 42 to prevent any buckling thereof when compressed. Thus, when bolt 22 is energized for recoil travel, the rear end thereof impacts against plunger 30 which acts through plate 44 against spring 42 to transfer the energy in the bolt thereto, as shown in FIG. 3. When bolt 22 comes to rest with all its energy transferred to spring 42 it is immediately driven forwardly by recovery of the spring for return to its battery position.

Only sufficient energy is transferred from spring 42 to bolt 22 for its return travel at a predetermined velocity so as to eliminate excessive impact thereof with other members of gun 12 when going to battery position. This is accomplished by stopping recovery of spring 42 at a predetermined location by a pair of sears 46 which are pivotally mounted on transverse pins 48 in housing 28 so as to be disposed diametrically apart therein. Each of sears 46 is provided at its rear end with a contact surface 52 which, when the sear is pivoted, is displaced between a blocking and a release position respective to plate 44. When front ends 54 of sears 46 are pivoted outwardly contact surfaces 52 are displaced inwardly to block forward travel of plate 44 at the predetermined location and when the front ends are pivoted inwardly the contact surfaces are disposed clear of the plate for release thereof. A spring 56 acts against each of sears 46 to press contact surfaces 52 thereon to the blocking position, as shown in FIG. 4.

Sears 46 are pivoted to the disengaged positions thereof, respective to plate 44, by a pair of levers 58 which are pivotally mounted in housing 28 forwardly of the scars and in longitudinal alignment therewith. The inside of each of levers 58 is provided with a cam surface 60 which is contoured in cross section to conform to the radius of body portion 32 and which inclines outwardly and rearwardly from the front end of the lever. Cam surfaces 60 are slidingly contactable by outer perimeter 62 of shoulder 36 during forward displacement of plunger 36 in housing 28, after sears 46 engage plate 44 to prevent full recovery of spring 42, to pivot front ends 64 of the respective levers 58 outwardly and rear ends 66 thereof inwardly. inwardly facing surfaces 68 on rear ends 66 of levers 58 are contactable with outwardly facing surfaces 70 on front ends 54 of sears 46 so that when rear ends 66 of the levers are cammed inwardly contact surfaces 52 of the scars are displaced outwardly, as shown in FIG. 5, for release of plate 44. Springs 72 act against levers 58 so that cam surfaces 60 thereon are pressed into contact with body portion 32.

OPERATION When gun 12 is ready for firing, as shown in FIG. 1, cartridge 18 is chambered in barrel l6 and bolt 22 is releasably held in battery position by restraining device 24. Upon discharge of cartridge 18 by a conventional firing mechanism (not shown) case 20 is set back in barrel 16 to energize bolt 22 for recoil travel. When adjacent its recoil position bolt 22 contacts forwardly extending stem 34 of plunger 30 which is displaced thereby rearwardly against spring 42. Thus, the energy in bolt 22 is transferred to spring 42 until the velocity of the bolt is reduced to zero. When no further energy is applied by bolt 22 to spring 42 the spring seeks to recover and transfer its stored energy back to the bolt which is energized thereby for counterrecoil travel to battery position.

When spring 42 recovers sufficiently for bolt 22 to be energized for its counterrecoil travel at a predetermined velocity, plate 44 is blocked against further forward displacement by contact surfaces 52 of sears 46. Through its inertia, however, plunger 30 proceeds forwardly in free travel moving perimeter 62 along cam surfaces 60 of levers 58 which is pivoted thereby to actuate inwardly facing surfaces 6% thereof against outwardly facing surfaces 70 of sears 46 and thereby displaces contact surfaces 52 outwardly for release of plate 44. Consequently, spring 42 is released to fully recover and discharge the remaining energy transferred thereto by bolt 22 after the bolt is located forwardly out of contact by plunger 30.

Iclaim:

1. In an automatic firearm comprising a member energized for reciprocal travel to and from a recoil position responsive to cartridge discharge forces, a buffer device including a plunger displaceable by contact of said'energized member thereagainst when adjacent the recoil position, energy absorbing means cooperating with said plunger for absorbing the energy in said member to reduce the velocity thereof to zero and for transferring a portion of the absorbed energy back through said plunger to said member for displacement thereof from the recoil position, sear means arranged to releasably block said energy absorbing means for limiting the amount of energy transferred back to said member to a predetermined portion of the total energy absorbed by said energy absorbing means, and sear release means operationally disposed between said sear means and said plunger so as to be actuatable thereby against said sear means for actuation thereof to release said energy absorbing means for discharge of the remaining energy therein free of said member.

2. The buffer device as defined in claim 1 wherein said plunger is arranged for free travel in said housing when said sear means releasably blocks said energy absorbing means against full transfer of the absorbed energy back to said member, and said sear release means is operationally disposed between said sear means and said plunger so as to be actuatable thereby during free travel thereof against said sear means.

3. The buffer device as defined in claim 2 wherein said energy absorbing means is of the type to store the energy absorbed thereby from said member in mechanical form and to discharge the energy remaining in said energy absorbing means in mechanical form.

4. The invention as defined in claim 2 wherein said buffer device includes a housing for enclosing the component parts thereof, said energy absorbing means include a coiled compression spring and a plate secured to a front end thereof, said plunger includes a body portion, a stem'extending from a forward shoulder on said body portion through said housing for contact by said member when adjacent the recoil position to actuate said plunger against said plate for compression of said spring, and a perimeter around said shoulder contactable with said sear release means for actuation thereof against said sear means during free travel of said plunger to release said energy absorbing means.

5. The buffer device as defined in claim 4 wherein said sear means include a pair of sears each of which is provided with a contact surface and is pivotally mounted to said housing for displacement of said contact surface between a blocking and a release position relative to said plate, and spring means disposed for cooperation with said sears for actuation thereof to displace said contact surfaces to the blocking positions, and said sear release means include a pair of levers each of which is disposed for cooperation with a respective one of said sears for actuation thereof to displace said contact surface thereon to the release position responsive to displacement of said plunger during the free travel thereof.

6. The buffer device as defined in claim 5 wherein each of said levers is provided with a cam surface contactable by said perimeter during free travel of said plunger to actuate said levers against said sears for release of said energy absorbing means.

7. In an automatic firearm comprising a reciprocal member energized each firing cycle for travel from a battery to a recoil position responsive to cartridge discharge forces transmitted thereto, the improvement comprising a buffer device including energy storing means for absorbing from said member during travel thereof to the recoil position the energy transmitted thereto for returning the stored energy back to said member for return thereof back to batteryposition, a first means for limiting the energy returned to said member by said energy storing means to only that portion of the total absorbed energy which is sufficient to return said member to the battery position at a predetermined velocity, and a second means cooperating with said first means for automatically discharging from said energy storing means in mechanical form free of said member the remaining energy absorbed thereby after said member is energized for return to battery position.

8. The invention as defined in claim 7 wherein said energy storing means consists of a resiliently'compressible member. 

1. In an automatic firearm comprising a member energized for reciprocal travel to and from a recoil position responsive to cartridge discharge forces, a buffer device including a plunger displaceable by contact of said energized member thereagainst when adjacent the recoil position, energy absorbing means cooperating with said plunger for absorbing the energy in said member to reduce the velocity thereof to zero and for transferring a portion of the absorbed energy back through said plunger to said member for displacement thereof from the recoil position, sear means arranged to releasably block said energy absorbing means for limiting the amount of energy transferred back to said member to a predetermined portion of the total energy absorbed by said energy absorbing means, and sear release means operationally disposed between said sear means and said plunger so as to be actuatable thereby against said sear means for actuation thereof to release said energy absorbing means for discharge of the remaining energy therein free of said member.
 2. The buffer device as defined in claim 1 wherein said plunger is arranged for free travel in said housing when said sear means releasably blocks said energy absorbing means against full transfer of the absorbed energy back to said member, and said sear release means is operationally disposed between said sear means and said plunger so as to be actuatable thereby during free travel thereof against said sear means.
 3. The buffer device as defined in claim 2 wherein said energy absorbing means is of the type to store the energy absorbed thereby from said member in mechanical form and to discharge the energy remaining in said energy absorbing means in mechanical form.
 4. The invention as defined in claim 2 wherein said buffer device includes a housing for enclosing the component parts thereof, said energy absorbing means include a coiled compression spring and a plate secured to a front end thereof, said plunger includes a body portion, a stem extending from a forward shoulder on said body portion through said housing for contact by said member when adjacent the recoil position to actuate said plunger against said plate for compression of said spring, and a perimeter around said shoulder contactable with said sear release means for actuation thereof against said sear means during free travel of said plunger to release said energy absorbing means.
 5. The buffer device as defined in claim 4 wherein said sear means include a Pair of sears each of which is provided with a contact surface and is pivotally mounted to said housing for displacement of said contact surface between a blocking and a release position relative to said plate, and spring means disposed for cooperation with said sears for actuation thereof to displace said contact surfaces to the blocking positions, and said sear release means include a pair of levers each of which is disposed for cooperation with a respective one of said sears for actuation thereof to displace said contact surface thereon to the release position responsive to displacement of said plunger during the free travel thereof.
 6. The buffer device as defined in claim 5 wherein each of said levers is provided with a cam surface contactable by said perimeter during free travel of said plunger to actuate said levers against said sears for release of said energy absorbing means.
 7. In an automatic firearm comprising a reciprocal member energized each firing cycle for travel from a battery to a recoil position responsive to cartridge discharge forces transmitted thereto, the improvement comprising a buffer device including energy storing means for absorbing from said member during travel thereof to the recoil position the energy transmitted thereto for returning the stored energy back to said member for return thereof back to battery position, a first means for limiting the energy returned to said member by said energy storing means to only that portion of the total absorbed energy which is sufficient to return said member to the battery position at a predetermined velocity, and a second means cooperating with said first means for automatically discharging from said energy storing means in mechanical form free of said member the remaining energy absorbed thereby after said member is energized for return to battery position.
 8. The invention as defined in claim 7 wherein said energy storing means consists of a resiliently compressible member. 